Relationship between proximate composition of food plants and Eri silkworm

Introduction

Eri silkworms (S. ricini) are economically significantsilk-producing insects endemic to the north-easternregions of India particularly Assam with widespreaddistribution in almost all the districts of Assam (Deand Das, 2010). These insects feed on a wide varietyof food plants, with castor (R. communis) being theprincipal feeding plant due to its ability to support theformation of high-quality cocoons. However, duringunfavorable seasons or periods of scarcity, erisilkworms also rely on secondary and tertiary hostplants, such as Manihot esculenta, Heteropanaxfragrans, Carica papaya, Evodia fraxinifolia,Jatropha curcas, Gmelina arborea, etc., asalternative food sources (Hazarika et al., 2003;Kumar and Elangovan, 2010). Leaf morphologicalfeatures and nutritional qualities of food plants varygreatly among varieties and locations (Kedir etal., 2014). Studies have shown that the food plantsused for rearing silkworms are the main determinantof silkworm growth and development, as well as thesynthesis of silk fibre (Mwchahary andBrahma, 2023). As herbivorous insects, eri silkwormrelies entirely on their host plant leaves for theirnutritional requirements. Different food plantscontain varying proportions of secondary metabolitesand nutritional components that can have a profoundeffect on eri silkworm growth, development and theeconomic characteristics of the resulting cocoons(Hazarika et al., 2005).

 Additionally, eri silkworm pupae have beenconsumed as a nutritive food source. Therefore, thecurrent study aims to provide scientific evidence ofthe relationship between the nutritional quality ofdifferent food plants used for rearing eri silkworm andthe proximate composition of eri silkworm larvae. Thefindings of this study could give information regardingthe selection of appropriate food plant for thecommercial production of eri silk, or formulation ofartificial diet with proper nutritional compositiontowards the future improvements of silk industry, aswell as contribute towards our understanding of theecology and biology of eri silkworm and theirinteractions with their food plants.